Background Fibromyalgia (FM) affects approximately 1-3% of the general population. Fatigue limits the work ability as well as the social life of patients with FM. A few studies of physical exercise have included measures of fatigue in FM, indicating that exercise can decrease fatigue levels. There is limited knowledge about the effects of resistance exercise on multiple dimensions of fatigue in FM.
Objectives To examine the effects of a person-centered progressive resistance exercise program on multiple dimensions of fatigue in women with FM, and to investigate predictors for the potential change in fatigue.
Methods A total of 130 women with FM (age 22-64 years) were included in this assessor-blinded randomized controlled multi-center trial examining the effects of person-centered progressive resistance exercise compared with an active control group. The intervention was performed twice a week for 15 weeks. Outcomes were five dimensions of fatigue measured with the Multidimensional fatigue inventory (MFI-20). Information about background was gathered collected and the women also completed several health-related questionnaires.
Multivariable stepwise regression was used to analyze predictors of change in fatigue in the total population.
Results A higher improvement was found at the post-treatment examination for change in the resistance exercise group, as compared to change in the active control group for the MFI-20 subscales General fatigue (Resistance Δ-1.3 SD 3.1, Controls Δ-0.5 SD 2.6, p=0.031), Physical fatigue (Resistance Δ-1.7, SD 4.3, Controls Δ0.0, SD 2.7, p=0.013) and Mental fatigue (Resistance Δ-1.6 SD 3.4, Controls Δ-0.1 SD 2.5, p=0.008).
Sleep efficiency was found to be the strongest predictor for change in the MFI-20 subscales General Fatigue (rs = -0.21, p=0.049) and for change in Reduced Motivation (rs = -0.22, p=0.037). Participating in resistance exercise (beta =1.90, p=0.010) and working less hours per week (beta =0.84, p=0.005) was independent significant predictors for change in Physical Fatigue (R2=0.14). Participating in resistance exercise was the strongest predictor for change in Mental Fatigue (p=0.008).
Conclusions Person-centered progressive resistance exercise improved multiple dimensions of fatigue in women with FM when compared to an active control group. Participating in resistance exercise, reporting poorer sleep efficiency and working less hours per week at baseline predicted improvement in multidimensional fatigue in women with FM.
Disclosure of Interest None declared